单分散ZnO微球的合成及表征

Synthesis of monodispersed ZnO microspheres and characterizations

采用简单的两步法合成了直径范围从50～200nm的单分散的ZnO微球:在第一步反应中制备了ZnO纳米粒子的乙醇分散液;然后在第二步反应中加入适量的ZnO纳米粒子的乙醇分散液,从而合成出单分散的ZnO微球.通过改变第二步反应中所加入的ZnO纳米粒子的乙醇分散液的量,可以改变制备的单分散ZnO微球的直径.通过透射电子显微镜和X-射线衍射分析可以得知,ZnO微球是由ZnO纳米粒子聚集而成.不论ZnO微球的直径是多少,其多分散指数均小于1,并且当ZnO微球的直径为150nm时,其多分散指数仅为0.16.

In this paper, monodispersed ZnO microspheres in sizes from 50 to 200 nmwere synthesized with a developed two-step method. In the primary reaction, ethanol suspension of ZnO nanopartieles was prepared, and monodispersed ZnO mierospheres were synthesized in the secondary reaction by adding the ZnO nanoparticles suspension into the reaetion solution. Diameter of the ZnO microspheres could be controlled by varying the volume of QDs suspension added. The transmission microscopy images and Xray diffraction patterns of the ZnO microspheres showed that no matter their diameters, the ZnO mierospheres were formed by aggregation of well crystallized ZnO nanoparticles. The polydispersity indexes （PDI） of ZnO microspheres were detected. It is found that PDI values of the microspheres were all less than 1.0, suggesting the monodispersity of the ZnO microspheres. The PDI value was only 0.16 when the diameter of the ZnO microspheres was 150 nm.